The present disclosure relates to a display apparatus capable of detecting an external approaching object, and more particularly to a touch detecting function display apparatus, a driving circuit, a driving method of the touch detecting function display apparatus, and electronic equipment including the same, capable of detecting a touch based on variations in capacitance.
In recent years, a display apparatus has attracted attention in which a display device such as a liquid crystal display device mounts a touch detecting function of detecting an external approaching object such as a finger therein, and information can be input instead of typical mechanical buttons by displaying various kinds of button images on the display device. Such a display apparatus with the touch detecting function tends to expand its use to a portable information terminal in the manner of a mobile phone and the like in addition to a computer, since an input device such as a keyboard, a mouse, or a keypad is not necessary.
The touch detection scheme includes several types, one of which is a capacitance type. For example, Japanese Unexamined Patent Application Publication No. 2009-258182 has proposed a display apparatus in which a common electrode for display originally provided in a display device is commonly used as one of a pair of electrodes for a touch sensor, and the other electrode (touch detection electrode) is disposed to intersect the common electrode. A capacitor is formed between the common electrode and the touch detection electrode, and the capacitance thereof is varied according to an external approaching object. The display apparatus, using this, analyzes a touch detection signal appearing at the touch detection electrode when a driving signal for touch detection is applied to the common electrode and detects the external approaching object. The display apparatus performs a display operation by sequentially applying the driving signal to the common electrode so as to perform line sequential scanning, and performs a touch detection operation by analyzing the touch detection signal appearing at the touch detecting electrode in response to the driving signal. At this time, by applying the driving signal to a plurality of common electrodes, improvement in the S/N ratio of the touch detection, that is, improvement in detection sensitivity of the touch detection is realized.